Friedrich adolf gottsch



(N0 Mddel.) F.'A.GOTTSUH.. v

UALGULATING CLOCK 0R DIAL.

No. 530,836. Pat ented Deor 11, 1894.

'NITED STATES PATENT Fries.

FRIEDRICH ADOLF GGTTSCH, OF KIEL, GERMANY.

CALCULATING CLOCK OR DIAL.

SPECIFICATION forming part of Letters Patent No. 530,836, dated December1 1, 1894. Application filed July 19,1894. Serial No. 517,996- (Nomodel.)

To all whom it may concern:

Be it known that I, FRIEDRICH ADOLF G6TTSOH, schoolmaster, of 31Eckernforder Ohaussee, Kiel, in the Empire of Germany, have invented anew and useful Calculating Clock or Dial, of which the following is aspecification, reference being bad therein to the accompanying drawings.

The subject of this invention is a calculating machine, similar to aclock or dial in its outward appearance, and which it is thereforeintended to call a calculating clock. It is adapted for use as a meansof teaching arithmetic, in schools; its object being to present to thestudents a great variety of arithmetical problemsor sums worked out in aclear and simple manner, the examples chosen belonging to any departmentof elementary arithmetic that may be required, although the improvedreckoning contrivance is by no means intended as a substitute for eitherthe usual manuals or exercise books, or for mental calculation as nowpracticed.

The object of the calculatingclock is only to provide the teacher, forcertain purposes and in certain cases, with an auxiliary means, both forfacilitating his own task of clearly expounding the theory of thedifferent processes of calculation, and for making the lessons asimpressive and fruitful as possible to his pupils.

The arithmetical clock is represented in the accompanying drawings,Figure 1 being a front elevation'of the complete clock, Fig. 2, asection thereof on line 00 a: Fig. l and Figs. 3 to 13 detail views,partly in elevation and partly in section.

A is the supporting plate consisting of a disk of cardboard, wood, orany other suitable material, on which the clock is mounted. It has a pinor spindle a in its center, whereon two other superposed disks B and 0,unequal in diameter, are adapted to turn. These disks are provided ontheir front and rear surfaces with a peripheral row of figures, thefigures on one side representingintegralnumbers and those appearing onthe opposite side being fractions, if required. The larger of the disksB, on either side carries a spring D adapted to move along the edge ofthe smaller disk 0 with slight friction and under the guidance of bothsimple and compound,"

or change such combinations as the problems to be dealt with mayrequire. Over the disks are placed two colored segment-shaped cardboardcovering plates E E, the central por 'tions of which are adapted to turnupon the spindle or pivot a, While the lower parts of their peripheriesare guided along a guide rod G by means of a friction clamp F (see Fig.8) in such a manner that the segments may, by simple pressure, bebrought nearer together, or moved farther away, from each other, as thecase may be.

The covering plates consist each of two sheets of cardboard, so attachedone above the other as to leave a recess or slot 1) or b correspondingwith each of the rows of figures, into which there may be slid a seriesof arc-shaped cardboard strips 0 c c and 0', bearing ones or naughts andserving to form numbers consisting of a l and one or more ciphers behindit. The lower portion of each of these covering plates is somewhatextended in the outward direction as at d d, so that those figures whichare situated next to the figures that happen to be dealt with in theproblem-in hand, are as completely as possible concealed from view. Ifnecessary the device may be supplemented bya pair of indices, concealingthe entire lower part of the figure-carrying disks or dials. By means ofa clamp H or H, either the larger or the smaller disk, after releasingthe spring D is alone turned. The auxiliary disk I similarly to theindices, consists of two cardboard plates or sheets, superposed andfixed together in such a manner that there is left an empty space at K KK, into whichspace is inserted a slip having one of the arithmeticalsigns X or according to the nature of the problem to be worked out,inscribed upon it. (See Fig. 12.) The auxiliary disk at the same .tlmeserves to secure the slip bearing the decimal point or comma, as shownat Fig. 13, for problems dealing with decimal fractions. The disk I ispassed on the pivot on over the two indices, and turned in such a mannerthat the sign, whatever it may be, takes up the position which, in thecourse of the calculation, it is supposed to occupy.

To prevent the disks or dials from slipping OK the pivot or spindle a,such spindle is pro- 5 vided with a nut.

The following are a few examples which will illustrate the manner inwhich the improved reckoning clock is to be used in practice.

The clock or combination of dials is best hung up on the usualblackboard, or on one of the walls of the schoolroom upon which therefalls sufficient light. The several dials or disks are then so adjustedas to suit the particular kinds of sums to be dealt with, and thenadjusted.

Suppose such sums as the following have to be worked out: 7+5, 9+2, 4+6,850. These being what may be called elementary sums with single figures,the indices E E should be so adjusted that the inner edge is directedtoward the mark 1. (See the scale at the upper edge of the dial.) Thechildren are then told to work out one sum after the other, the dialsbeingat each fresh sum turned a space corresponding to one figure,either with the finger or by the aid of a piece of india-rubber or thelike.

In the case of problems with numbers cornposed of two figures, such as:48+17, 63+58, 36+7 l, &c., the indices should be placed against the mark2. In the case of numbers consisting of three figures, they should bebrought opposite to the mark 3. In the case of numbers consisting offour figures, they should be brought up to the mark 4.

The circular rows of figures on the two disks include the numbers 2 to9, which do not follow each other in their normal order. WV-hen it isdesired by means of these figures to form numbers having a 1 for theirfirst figure in front, or an O for their last figure (for example, 16,124, 1538,40,600,8000), the cardboard slips c, c, c, c (Fig. 5) areinserted into either the upper or the lower slot (1) or 11') of one ofthe two indices.

In forming series of problems such as the following: -44, 17, 40-16,due, it will be necessary to insert, for example, a O. at the top on theright, and a 1 below on the left (Fig. 1).

As regards the employment of the auxiliary disk I. this has already beenwith sufficient clearness set forth above. The master will, of course,please himself as to whether, and to what extent, he will make use ofthe small cardboard slips, bearing the arithmetical signs X, and: asthese signs are not absolutely necessary, not being generally used 60 inmental calculation, especially in the elementary stage, where childrenare simply told to add, take off, &c.; some colloquial phrase replacingthe expressions plus, minus, the. WVhere, however the slips in questionare employed, they may,in addition to fulfilling their proper ororiginal object, be made serviceable in a variety of secondary ways. Insuch problems as: 84=+9, 56+8, &c., the plus slip may be so turned, forexample, as to make the plus sign serve at the same time for coveringover the tens in the lower number, so that for this purpose, a specialwhite slip need not be inserted.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is-- 1. In a device for teaching arithmetic the combination withthe concentric dials of different diameters provided with numerals, ofcovering plates adjustable toward and from each other to expose one ormore characters of each dial, substantially as described.

2. In a device for teaching arithmetic the combination with theconcentric revoluble dials, of the covering plates, adjustable towardand from each other to expose one or more characters of each dial, saidplateshaving recessed portions to receive removable characters,substantially as described.

3. In a device for teaching arithmetic the combination with theconcentric revoluble dials, of covering plates adjustable toward andfrom each other to expose one or more characters of each dial, a deviceprovided with sockets and removable parts bearing the signs indicatingarithmetical operations adapted to engage said sockets, substantially asdescribed.

4. In a device for teaching arithmetic the combination with therevoluble concentric dials provided with numerical characters, of thesegmental covering plates, adjustable toward and from each other toexpose one or more characters on each dial, and spring clips forsecuring said dials in position, with respect to said covering plates,substantially as described.

5. In a device for teaching arithmetic the combination with thesupporting plate, provided with a guide rod, of concentric calculatingdials, covering plates provided with devices frictionally engaging saidguide rod for adjusting said plates from and toward each.

other, substantially as described.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

FRIEDRICH ADOLF co'rrsou.

Witnesses:

CARL KRAUSE, HERMAN I'IOLSTINS.

IIO

